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Discussion Starter #1
Hello All,

I have been experiencing a vibration/quiet moan when the RPM is between 2250 and 3000 whether the car is moving or stopped. I think it may be the center driveshaft guibo which has a small crack but Im not sure. Any Ideas?

Thanks,

Miguel
 

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If you get a vibration at a certain range of revs, odds are high that the driveline is now slightly out of balance due to the cracked guibo which has most likely changed shape due to the cracking. The vibration occurs at a certain rev range because that is associated with the fundamental rotational resonant frequency of that driveline/guibo system.

This is similar to a tire out of balance causing the greatest steering wheel vibration at speeds of around 60-70 mph, because that speed range represents the fundamental resonant frequency range of the typical car front suspension spring/mass/damper system.

I suspect that the cracked guibo won't last too long, developing more cracks, and the vibration will get worse until the guibo fails entirely.

Of course, it could be something else, but the failing guibo is the most likely candidate.
 

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Me Winta Beata also has this feeling as well and I checked the drive shaft and all was good. The rubber was NOT cracked and in good shape. Almost think it's a motor mount since it seems it's coming from the front of the car when in neutral with the clutch out?
 

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Discussion Starter #5
OH.... I just remembered that the rear motor mount is going so that probably has contriubted to the problem too.
 
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